Stereoselective Formation of Functionalized 2-Aryl-tetrahydrofurans from Aromatic Aldehydes via Intramolecular 1,3-Dipolar Cycloadditions (INOC and IOOC)
作者:Alfred Hassner、K. M. Lokanatha Rai、Wim Dehaen
DOI:10.1080/00397919408010169
日期:1994.6
SnCl2-2H2O in the presence of an unsaturated alcohol, undergo either thermally induced intramolecular oxime olefin cycloaddition (IOOC) to bicyclic isoxazolidines 7, with stereospecific introduction of three stereocenters, or nitrile oxide olefin cycloadditions (INOC) to bicyclic isoxazolines 6. This provides an entry into functionalized tetrahydrofurans and tetrahydropyrans.
摘要 α-烯丙氧基醛肟 8 是在不饱和醇存在下用 SnCl2-2H2O 还原 β-硝基苯乙烯 5 形成的,通过热诱导分子内肟烯烃环加成 (IOOC) 生成双环异恶唑烷 7,同时引入三个立体中心,或氧化腈烯烃环加成 (INOC) 到双环异恶唑啉 6。这提供了进入官能化四氢呋喃和四氢吡喃的入口。